Building a snapshot of the current coreutils with current gnulib, I get
a compilation error on CentOS 5 and 6:

  CC       src/ls.o
../src/ls.c: In function 'gobble_file':
../src/ls.c:3556: error: 'XATTR_NAME_CAPS' undeclared (first use in this function)
../src/ls.c:3556: error: (Each undeclared identifier is reported only once
../src/ls.c:3556: error: for each function it appears in.)
make[2]: *** [src/ls.o] Error 1

The attached proposed patch fixes it.
This is a similar problem as we encountered in gnulib:
https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=3266c08a315
https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=73a13b94b94
The lesson is: Provide fallbacks for *all* XATTR_NAME_* values, since older
distros don't define them.